Tuesday, March 17, 2026

[Botany • 2026] Begonia mizoramensis (Begoniaceae, sect. Platycentrum) • A New dioecious Species from Mizoram, Northeast India

 

Begonia mizoramensis Vanlalawmpuia, Khomdram & Yumkham,  

in Sailo, Khomdram, Yumkham, Lalthantluanga et Khiangte, 2026. 

Abstract
Begonia mizoramensis (Begoniaceae) under Begonia sect. Platycentrum (Klotzsch) A.DC. is described as a new species from Mizoram, Northeast India. It shares similarities in habit, leaf morphology and inflorescence with Begonia longifolia Blume and Begonia acetosella Craib, but differs in several characters, including longer internode, anthers with dehiscence extending beyond half their length, shorter pedicel in pistillate flower and a puberulent ovary with unequal wings. Taxonomic notes and pollen micromorphology are presented to confirm its novelty and sectional placement. Based on the available data, the newly discovered species has been provisionally assessed as Critically Endangered (CR) under the IUCN Red List Categories and Criteria.

Keyword: Begonia acetosella, Begonia longifolia, Begonia mizoramensis, Indo-Burma Hotspot, Mizoram, Platycentrum

Begonia mizoramensis Vanlalawmpuia, Khomdram & Yumkham sp. nov.
A. Male flowering branch and rhizome. B. Stem base and rhizome; C. Internodes; D. Stipule, E. Leaves (adaxial), F. Leaves (abaxial); G. Staminate flower; H. Male tepals. I. Stamen. J. Pistillate flower. K. Female tepals. L–M. Frontal (L) and side (M) view of ovary and stigma. N. Immature fruit. O. Cross section of ovary.


Begonia mizoramensis Vanlalawmpuia, Khomdram & Yumkham sp. nov.
 A–B. Habit (A. inset rhizome). C–D. Flowering twigs of male flowers (bee pollination in D). E. Solitary female flower, F. Flowering twig (abaxial surface). G. Portion of leaf (adaxial surface). H. Portion of leaf base with petiole (abaxial surface). I. Bracts. J. Stipules. K–M. Male Flowers. N. Androecium. O. Stamen showing dehiscence line.

Begonia mizoramensis Vanlalawmpuia, Khomdram & Yumkham, sp. nov.  
 Section Platycentrum 

Diagnosis: Begonia mizoramensis resembles B. longifolia and B. acetosella in habit, leaf morphology and inflorescence but differs by anthers with dehiscence extending beyond half their length, shorter pedicel in pistillate flower (3 mm) and puberulent ovary with unequal wings. B. mizoramensis differs from B. longifolia in sexuality (dioecious vs. monoecious), pedicel in staminate flowers (7–11 mm vs. 25–30 mm) and ovary (puberulent, not inflated vs. glabrous, slightly crested, inflated). It also differs from B. acetosella in peduncle (1– 5.5 mm long, glabrous vs. 2–10 mm long, puberulous), tepal number in pistillate flower (6 vs. 4) and in ovary (3- loculed vs. 4-loculed). 
 
 
Vanlalawmpuia Sailo, Sandhyarani Devi Khomdram, Sanatombi Devi Yumkham, Renthlei Lalthantluanga and Laldinliana Khiangte. 2026. Begonia mizoramensis (Begoniaceae, section Platycentrum), A New dioecious Species from Mizoram, Northeast India.  Taiwania. 71(2); 213-220. DOI: 10.6165/tai.2026.71.213 [17 March 2026]